The ABCDEs of skin cancer are five warning signs of melanoma. Melanoma is the most serious type of skin cancer. Each letter stands for a feature that describes a cancerous freckle or a mole:

• A is for asymmetry. One half of the mole doesn’t match the other.
• B is for border. It has uneven or blurred edges.
• C is for color. It has multiple colors or shades.
• D is for diameter. A mole is larger than a pencil eraser.
• E is for evolving. Any change in size, shape, color or height — or new symptoms like itching or scabbing — should be checked by a provider.

If you notice any of the ABCDEs of skin cancer, call your provider right away. An early diagnosis and treatment improve outcomes.

Why should I check my skin for early signs of melanoma?

Melanoma is serious, but it’s highly treatable when caught early. That’s why it’s important to check your skin regularly. You know your skin best, so you’re most likely to spot changes, like a new mole or a freckle that looks bigger or crustier than before. Catching these signs early gives you the best chance for a cure.

What’s the ugly duckling sign of melanoma?

If you have lots of freckles or moles, you might notice one that looks different from the rest. Maybe it’s scabbed over, has grown or is more raised than before. That one spot stands out. That’s what providers call the “ugly duckling” sign. Just like in the childhood story, it refers to a mole or freckle that doesn’t match the others. It could be a warning sign of melanoma.

How do I check my skin for melanoma?

You can perform this skin check at home. Use a well-lit room, a full-length mirror and a hand mirror. Follow these steps:

1. Start with your front and back. Use the full-length mirror to examine your entire front and back.
2. Check both sides. Raise your arms and look at the left and right sides of your body.
3. Look inside your mouth. Check your lips, tongue and inner cheeks.
4. Examine your arms and hands. With your elbows bent, check your forearms, upper arms, palms and between your fingers.
5. Check hard-to-see areas. Use mirrors to look at your back, butt and genital area.
6. Lift your breasts. If you have breasts, lift them to see the skin underneath.
7. Look at your legs and feet. Sit down if needed. Check the backs of your legs, soles of your feet and between your toes.
8. Check your scalp and neck. Use both mirrors to inspect the back of your scalp and neck. Part your hair or use a blow dryer for a closer look. Ask your hairdresser or barber to point out any unusual spots.

During your self-exam, note any moles, blemishes or birthmarks from head to toe. Use a small ruler to measure their size, and watch for changes in color, shape or size, or any sore that doesn’t heal. Taking photos can help you track changes over time.

How often should I examine my skin?

Check your skin about once a month, ideally after a bath or shower. Keep track of any spots or changes and where they appear. Contact your provider if you notice anything new or changing.

What are the benefits of a skin self-examination?

Checking your skin may feel unfamiliar at first, but it’s a simple habit that comes with real power. There’s no harm in doing it, and it could help you spot something important.

Skin changes often appear slowly. Getting to know your skin well means you’ll be able to easily spot when something’s out of place. That awareness may lead to faster answers. Catching skin cancer in its early stages gives you more options — and a much better shot at successful treatment.

But don’t panic — not every skin change is cancer. And not every lesion that meets the ABCDE or ugly duckling criteria is skin cancer. You should still trust your instincts. And if something doesn’t look or feel right, reach out to your provider. A quick check-in could make all the difference.

When should I call my doctor about a change in my skin or a mole?

Reach out to your provider if you notice:

• A change in the size, color or shape of an existing mole or skin marking
• A sore that doesn’t heal
• A mole that itches or bleeds

Your dermatologist can evaluate and treat suspicious areas early. They’ll also track any changes over time. If you’re at a higher risk for melanoma or other skin cancers, your provider may recommend regular checkups.